Digital Rights Management is a term used to describe the concept of protecting copyrighted material via encryption and governing its access via rules, typically distributed independently of the content. The protected content is usually inaccessible without a legitimately acquired license (embodying the rules governing the access) and software that securely interprets and releases the content if the appropriate license is available. This technology is promoted widely to music labels and other music/content distribution companies to use as a core technology for protecting their content.
Certain content encryption problems arise especially in the context of streamable media (e.g. media such as music or video that may be streamed across a network and rendered (e.g., played) while being streamed rather than after the entire content is received or when read from a local file). In these cases, encryption may need to be done in real time, and lossy transport protocols may cause situations where not all the content sent is ever received at the client. For example, lost blocks of encrypted data may cause the entire file to be unreadable. Furthermore, certain encryption techniques may increase the size of the digital content file.